Radiation exposure
โข๏ธ Radiation exposure can come from natural sources (radon gas, cosmic rays, radioactive minerals) or human-made sources (medical imaging, nuclear power, radiotherapy).
While radiation has important medical uses, uncontrolled exposure can cause serious harm to health.
โก Types of Radiation
- Ionizing Radiation โก
- X-rays, gamma rays, alpha particles, beta particles, neutrons.
- High energy โ ionises atoms โ DNA damage & tissue injury.
- Non-ionizing Radiation ๐ก
- UV rays, visible light, infrared, microwaves, radiofrequency.
- Lower energy โ less harmful, but UV can cause skin cancer.
๐งฌ Biological Effects of Ionizing Radiation
- Cellular Damage ๐ฌ
- Direct DNA damage or indirect ROS (free radicals).
- Can lead to mutations, cell death, or malignancy.
- Deterministic Effects (dose-dependent) ๐
- Severity โ with dose.
- Burns, radiation sickness, organ failure.
- Examples: skin erythema, alopecia, cataracts, ARS.
- Stochastic Effects (probability-based) ๐ฒ
- Risk โ with dose, severity not dose-related.
- Cancers (leukaemia, thyroid, lung, solid tumours), genetic mutations.
๐จ Acute Radiation Syndrome (ARS)
- Hematopoietic Syndrome (1โ10 Gy) ๐ฉธ โ marrow failure โ anaemia, infection, bleeding.
- Gastrointestinal Syndrome (10โ20 Gy) ๐ฝ๏ธ โ nausea, vomiting, diarrhoea, dehydration.
- Cerebrovascular Syndrome (>20 Gy) ๐ง โ neurological collapse, coma, death within days.
โณ Long-term Effects
- Cancers ๐๏ธ โ leukaemia, thyroid, breast, lung, solid tumours (latency yearsโdecades).
- Genetic Effects ๐ถ โ heritable mutations, congenital anomalies.
- Cardiovascular Disease โค๏ธ โ vascular & heart damage, โ risk of stroke & MI.
- Chronic Radiation Syndrome ๐ด โ fatigue, memory loss, immune dysfunction from prolonged low-dose exposure.
๐ก๏ธ Protection & Mitigation
- โฑ๏ธ Time: Minimise exposure duration.
- ๐ Distance: Stay as far from source as possible.
- ๐งฑ Shielding: Use barriers (lead aprons, concrete walls).
- ๐งค PPE: Gloves, masks, protective clothing for handling materials.
- ๐ Monitoring: Dosimeters to track exposure.
- ๐ Regulations: Follow ICRP & NCRP safety standards.
๐ Common Radiation Doses (Examples)
- ๐ Eating a banana: ~0.1 ฮผSv
- ๐ฆท Dental X-ray: ~5 ฮผSv
- ๐ซ Flight (LA โ NYC): ~40 ฮผSv
- ๐ซ Chest X-ray: ~0.1 mSv
- ๐ฅ๏ธ Chest CT: ~7 mSv
- ๐ง Whole-body CT: ~10 mSv
- โค๏ธ Coronary CT Angio: ~12 mSv
- โ๏ธ PET/CT: ~25 mSv
- ๐ท Radiation worker limit (1 yr): 50 mSv
- ๐ฅ Chernobyl emergency worker: ~0.25 Sv
- ๐ฅ Hiroshima survivor: ~0.5 Sv
- โ ๏ธ 8 Sv: lethal (50โ100% mortality in 7 days, even with treatment)
๐ Summary
Radiation can cause harm ranging from acute radiation syndrome to late cancers & genetic effects.
Understanding dose, type, and protective measures is essential for safe use, especially in medical & nuclear settings.
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